Success! The installation was quite a challenge, since we were working on a slope with all four legs of the arbor having to be different lengths to keep the top level. Oh and we were installing it right next to a gate with cement footings where two of the posts had to go. But we got creative, and here's the result:
As you can tell from the pictures, by the time we finished, the sun was yet again beating down on us, but we sure feel accomplished!
Now to plant the fast-growing red-flowed vine my boss gave me beans for.